Trying to format a USB-C drive to APFS - it is not available?

[pax-eterna]

Attached the Samsung T7 to erase and format to APFS. However APFS is not available as an option. Only MAC Extended and journaled, for whatever that means.

I read that I need to format the "container" not the "volume" inside the container, however I also can not access that. All I can access is the T7 Volume, and that option is only those formats noted above.

I did note it was an ex-fat drive, although why Samsung did that on such a large drive I'm not sure? So I've gone back to the W11 machine and doing a clean/diskpart and creating to NTFS and seeing if that makes a difference in Sonoma.

Any other ideas?

 

[pax-eterna]

Ok got it sorted out a bit more - needed to select see all drives from drop down.

So now I cannot rename the main SSD from the Samsung Factory name, or is this actually embedded into the hardware? (must research that)

Now, what happens when I select Erase, is it creates this container, and THEN the data folder I am trying to create, in the meantime using about 30 gigabytes of space!!!

All I want to do is create one container under the main SSD Drive..

So what am I missing, or not doing correctly?

 

[gwang73]

Change the scheme to GUID Partition.

ExFat is good for multi-platform compatibility. Mac can't write to NTFS without third party solution and APFS is only supported by Apple.

 

[pax-eterna]

Change the scheme to GUID Partition.

ExFat is good for multi-platform compatibility. Mac can't write to NTFS without third party solution and APFS is only supported by Apple.

thanks, yeah that's what I ended up doing....just cannot figure out how to show the MacOS Data folder (not the attached USB drive) as I cannot see Finder Preferences, they are simply not available. All I get is a list of files on the left. I am trying to place that data folder on to the desktop so I can easily transfer my existing data (Windows) to it...

 

[gilby101]

Don't go to Windows to format a disk which will be used on a Mac.

In Disk Utility, select the disk called Samsung PSSD T7 Media (or similar), click the erase button (top of the drive's window), choose GUID partition map, APFS format, give it a name and click erase. Just to be sure, like this:

This will, as it warns, erase all data on the disk, removing all the existing partitions.

You will end up with:
The physical drive (Samsung PSSD T7 Media),
A partition (APFS Container), and
The new volume in APFS format.

Later, if you wish, you can add more volumes to the container. The volumes share the size of the container.

 

[pax-eterna]

Thanks

I am really not sure what I am looking at here...can someone explain this to me, and why there are so many volumes and folders that make no sense to me?

Also that last folder App Data, is where I need to copy my existing app databases into...but in Finder I cannot locate it anywhere?

 

[gwang73]

thanks, yeah that's what I ended up doing....just cannot figure out how to show the MacOS Data folder (not the attached USB drive) as I cannot see Finder Preferences, they are simply not available. All I get is a list of files on the left. I am trying to place that data folder on to the desktop so I can easily transfer my existing data (Windows) to it...

When you open Finder from the Dock, the folders shown are what's stored in your user account on your Mac.

If you're familiar with Linux, Mac is similar to that on how it handles volumes vs. drives on Windows.

 

[gilby101]

What you are seeing:

The easy part:

Physical drive: Apple SSD AP0512Z Media with:​

Container disk3 - this is a partition formatted for APFS and contains:​

"Macintosh HD volumes" (see below) - these are APFS volumes, and​

A few hidden volumes used for recovery, booting and virtual memory.​

This is where it gets tricky and you will only see this on your boot disk.

The "Macintosh HD volumes" is a combination of:

"Macintosh HD" (the grey one) - this is the read only volume containing the parts of macOS which are the same on all Macs,​

"Macintosh HD snapshot" is the currently mounted version of Macintosh HD,​

and​

"APP DATA" - this has the writeable part of macOS, your apps, settings and data. Normally this is named "Macintosh HD - Data", but you must have changed it.​

Now we come to what Finder is doing:
All the complications of the above are hidden by Finder and, with some magic called firmlinks, combines the mounted "Macintosh HD snapshot" with "Macintosh HD - Data" (APP DATA on your Mac) into a single volume and presents that as "Macintosh HD".

If want an additional volume to hold specific data (files and folders) then, in Disk Utility, select the Container disk 3 and click on the + symbol to add a new volume. Clicking on the + is the same as using the menu item Edit > Add APFS volume. But don't call it APP DATA as you already have a volume called that.

As comments on what you are doing: You should not add additional volumes without a good reason. The boot/system disk is best left alone until you are confident in what you are doing.

 

[pax-eterna]

@gilby101 Cool, thanks - coming straight from Windows 11 (previous long term windows user) bit of Linux experience which is why I thought this would be similar. hahaha, but it's different again.

I guess I am used to seeing File Explorer in Windows, which makes viewing and loading to these folders very easy!
As you say I am not sure about it so I will leave it all at default for the moment (apart from following your directions on creating that data drive).

I have actually just completed a full uninstall and reinstall of Sonoma so I could start from scratch again

 

[pax-eterna]

When you open Finder from the Dock, the folders shown are what's stored in your user account on your Mac.

If you're familiar with Linux, Mac is similar to that on how it handles volumes vs. drives on Windows.

Ahhh, yes ok...Now you mention that, this is much like Linux - I will try to "invoke" my Linux experience

 

[pax-eterna]

A few hidden volumes used for recovery, booting and virtual memory.

On this subject, with 16gig of RAM, do I really need virtual memory? I know on windows I could safely turn it off.

Is it possible to turn Virtual Memory off in Mac? Or is it better managed (IE is totally off unless absolutely needed) on MacOS?

 

[pax-eterna]

Of all the folders mentioned above, which gets deleted if there is a re-install of the OS, or most likely, when MacOS goes to 15?

 

[gilby101]

Is it possible to turn Virtual Memory off in Mac?

Yes, but don't. The virtual memory is for the swap file. If memory management does not need a swapfile, then it won't take space. But if it is needed, you avoid any sudden shutdown. macOS memory management prefers to compress memory and only uses the swapfile when really needed. User attempts to tweak memory management usually end in tears.

Of all the folders mentioned above, which gets deleted if there is a re-install of the OS, or most likely, when MacOS goes to 15?

No volume gets deleted. For all point updates (e.g. to 14.2 or 14.2.1) and for upgrades (e.g. to 15) the read-only Macintosh HD gets updated and signed with a new signature. Upgrades to next major release will replace more of the content. Macintosh HD - Data will be updated where there are changes to settings or to formats of databases. The old snapshot gets deleted - but that is equivalent to deleting all the old macOS files.

Edit: This no longer true (see comment below from @Mike Boreham). I should have known.
The complication of the snapshot is to avoid issues when an update gets aborted part way through if, for example, the power goes off or there is some file corruption preventing the install. The snapshot allows going back to previous version.

 

[pax-eterna]

Yes, but don't. The virtual memory is for the swap file. If memory management does not need a swapfile, then it won't take space. But if it is needed, you avoid any sudden shutdown. macOS memory management prefers to compress memory and only uses the swapfile when really needed. User attempts to tweak memory management usually end in tears.

No volume gets deleted. For all point updates (e.g. to 14.2 or 14.2.1) and for upgrades (e.g. to 15) the read-only Macintosh HD gets updated and signed with a new signature. Upgrades to next major release will replace more of the content. Macintosh HD - Data will be updated where there are changes to settings or to formats of databases. The old snapshot gets deleted - but that is equivalent to deleting all the old macOS files.

The complication of the snapshot is to avoid issues when an update gets aborted part way through if, for example, the power goes off or there is some file corruption preventing the install. The snapshot allows going back to previous version.

Very cool, thanks gilby - I will take your advice and leave the swap alone, as I thought, your comments seem to confirm MacOS handles virtual RAM differently to Windows.

And I understand re the volumes as well, NOW, thanks to your assistance, much appreciated!

 

[Mike Boreham]

The complication of the snapshot is to avoid issues when an update gets aborted part way through if, for example, the power goes off or there is some file corruption preventing the install. The snapshot allows going back to previous version.

This was true at one point (pre Big Sur) but currently the local snapshots do not allow rollback to a previous version of macOS. They only roll back the -Data volume. There is an Howard Oakley (Eclectic Light) article, plus I have verified by testing.

 

[Saturn007]

Had same issue about how to format a T7 with APFS.

A key step is missing here -- View menu, Show All Devices, and then select the parent of the T7. Thanks to Delta Mac in another thread for providing the solution!

Format Sumsung T7 to APFS but AFPS not available?

Thank you! This was the perfect solution trying to get my Samsung PSSD T7 Shield formatted as APFS: Change the scheme to GUID Partition Map 👍

forums.macrumors.com

"In Disk Utility, choose the View tab (or the View menu) and change to Show All Devices.

With your T7 attached, choose the top line for that T7 (shows the drive information/model number), then choose erase. You will now find that you can change the Format to APFS, if that's what you want.

If you still don't see that as a choice, make sure to change the "Scheme" to "GUID Partition Map". It is probably set for Master Boot Record, which won't allow APFS format."

 

[Fishrrman]

There's no reason to format a flash drive APFS.

Plain old HFS+ is good enough.
(Mac OS extended, journaling enabled, GUID partition format)

 

[Ben J.]

Wikipedia:

Apple File System​

Both HFS+ and APFS are completely fine, but APFS has some extra features/optimizations; snapshots, 64bit etc.

One thing I think makes a very big difference is that a volume on APFS doesn't have a fixed size. All volumes in a container share the free space. (BTW, you can still partition a drive and set the partitions to different formats. The partition sizes are fixed.)